I've been hosting my own email on this domain for just over a year now and I hadn't noticed any problems until a couple of days ago a German friend of mine using GMX tired to send me an email and it bounced back with the error message "no valid …

At work yesterday we got a couple of phishing email claiming to be traffic infringements, nothing too remarkable about that. But interestingly this time the links in the emails to Bitly, a url shortener service that redirects traffic instead of going directly to some hacked site hosting malware.

With Bitly …

You can send an email using telnet it's very useful for debugging. It's something I've done several times before but because it's not something I do regularly I always forget the exact syntax so I've written this as a Note to self to remember the commands.

Finding the mail server …